Senior Member

I agree with Thomas that "whereas" cannot be replaced with "on the contrary" in mimi2's first sentence:

"Some people like meat with a lot of fat on it. On the contrary, others hate it."
"Some people like meat with a lot of fat on it. Others, by contrast, hate it."
"Some people like meat with a lot of fat on it, while others hate it."
"Some people like meat with a lot of fat on it, but others hate it."
"Some people like meat with a lot of fat on it, whereas others hate it."